In the twentieth century, western music began to branch out in many different directions. In the early twentieth century, composers like Gustav Mahler and Richard Strauss continued to write dramatic, expressive music as a natural continuation of the Romantic trends.

At the same time that impressionist painting flourished in France, composers like Claude Debussy and Maurice Ravel explored a complimentary musical style. Impressionist music made greater use of dissonance (notes that sound unstable or “rub” against each other) and moved away from the structures of major and minor tonality.

In reaction to the atrocities of war, German composers like Arnold Schoenberg wrote Expressionist music that was often intensely jarring and unsettling to listen to. This style led to experimental styles like serialism, in which composers abandoned tonality altogether and approached their music like a puzzle to be assembled. The style was appreciated by intellectual musicians, but it did not achieve popularity.

Some composers embraced the rich traditions of western art music while incorporating contemporary influences. Aaron Copland was a significant American composer who made fresh use of dissonance and incorporated jazz and folk elements while maintaining the elegance of the classical style.

John Cage, another American composer, is best known for his unusual use of the piano. He wrote several pieces for prepared piano in which items like paper clips and bottle caps were placed on the piano strings to create unusual sounds. He is perhaps best known for his piece titled 4’3’’ in which the pianist sits quietly for four minutes and thirty three seconds. The music is created not by the piano but by the ambient noise in the room.

American composer Philip Glass pioneered the Minimalist style, in which short musical fragments are repeated and layered to create a hypnotic effect. This is a style that is still used today by some film composers, and it is similar to the way that DJs sample songs.

In the mid twentieth century, jazz music achieved widespread popularity in American cities as well as with young Europeans. Broadway show tunes were also well-loved. With a radio in nearly every household, these musical styles were easily transmitted to a wide audience, and they soon replaced art music as the dominant musical styles. In the 1950s, rock and roll claimed the spotlight and would reign in popularity for the remainder of the century.